unless her damage is tripled. especially on her Q. generally when it comes to supports, riot uses the excuse that a champion having only one damaging basic ability that that ability should nuke people. (see 
) so why the heck does a Q that has awkward aiming and awkward mechanics do half the damage of sona's Q? And it dosen't do splash damage? Excuse me?
Shes a better Sona? Her R alone can get 700-1200 damage and she has a giant shield thats essentially never down if shes not dead
Q is way less committal too. Supports don't actually need nukes 
Its because her Q is very easy to land AND it can nuke. -in short. My suggestions for her are to: 1.Increase projectile speed. This will make it harder to land shots against enemies who attempt dodges and sidesteps and yet; give her power securing fleeing enemies. 2.Give her 20 dmg back on her Q at the last 3 ranks. (She needs ONE damaging ability and the fact its now more of a skill-shot and less relyable allows for damage to be put pack)
Also, Yuumi got that damage REPEATEDLY, every 9s or so. Sona has to cast 3-4 times to have her charge for bonus damage- then auto. Yuumi just needs range.
All in all- Yuumi either needs a flatout Q overhaul or they need to give her at least 1 damaging ability. Even with full AP builds it deals 0 damage. lol
